Sealing assemblies

ABSTRACT

This invention is directed toward improved liquid sealing assemblies. The sealing assemblies are particularly useful in water control gates and in one embodiment have an elastomeric seal strip with a U-shaped cross-section defined by a web and a pair of arms extending transversely from the web. The seal strip is adapted to be fastened to a sealing location by mounting means located between the arms of the seal strip. The web of the seal strip is sandwiched between the mounting means and the sealing location, with the arms of the seal strip projecting just past the mounting means to effect sealing with their free ends. 
     In another embodiment, the sealing assemblies have first and second elastomeric seal strips adapted to be mounted on two relatively movable members. One of the seal strips, mounted on one of the members, has a bendable portion that projects into the path of relative movement of the other seal strip mounted on the other member so that when the seal strips abut, the bendable portion gives slightly to give better sealing between the seal strips. 
     The invention is also directed toward water control gates incorporating the sealing assemblies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is directed toward improved scaling assemblies.

The invention is also directed toward a control gate constructionincorporating the improved scaling assemblies.

2. Description of the Prior Art

Control gates, employing a slide to close an opening within a wall, arewell known. The slide is moved up or down within guide means mounted onthe wall adjacent the vertical sides of the opening. Side scaling meansare provided in the guide means, extending parallel to the direction ofmovement of the slide, to seal the slide to the guide means and thus tothe wall to prevent water or other liquid from flowing past the sides ofthe slide. Bottom sealing means are provided on the wall adjacent thebottom of the opening to seal the bottom of the slide to the wall toprevent water or other liquid from flowing past the bottom of the slidewhen in a closed position. Top sealing means are also provided on thewall adjacent the top of the opening to seal the top of the slide to thewall. The top and bottom sealing means extend transverse to thedirection of movement of the slide. Thus the opening is sealed on allfour sides by the slide and the sealing means when the slide is in aclosed position. Examples of seals in water control gates extending in adirection parallel to the direction of movement of the slide are shownin U.S. Pat. Nos. 2,643,521; 2,984,074; 3,326,002 and 3,371,493.Examples of scale extending in a direction transverse to the directionof movement of the slide are shown in U.S. Pat. Nos. 2,643,521 and2,984,074.

For most slides, elastomeric seals provide the best sealing arrangement.However, it is often difficult to obtain a good tight seal withelastomeric seals. Elastomeric seals also wear rapidly and thus theymust be mounted in a manner whereby they can be easily replaced. Mostknown elastomeric seals used on the sides of a slide are constructed toprovide a sealing surface on one side only of the seal. Thus, the knownseals cannot always provide suitable sealing for the slide with water oneither side of the slide. Most known elastomeric seals used on the topand bottom of the slide are of the type requiring abutting surfaces.However both the top and bottom abutting surfaces must abutsimultaneously to obtain a good sealing and this is difficult toarrange.

SUMMARY OF THE INVENTION

It is the purpose of the present invention to provide improved sealingassemblies for control gates which give better sealing than knownsealing assemblies, and which can be easily replaced if needed. It isanother purpose of the present invention to provide sealing assemblies,particularly sealing assemblies extending in a direction parallel to thedirection of slide travel, which are double acting in the sense thatthey seal no matter which side of the slide the water is on. It is afurther purpose of the present invention to provide sealing assemblies,extending in a direction transverse to the direction of movement of theslide, which wedge together allowing better sealing simultaneously atthe top and bottom of the slide. It is another purpose of the presentinvention to provide an improved control gate construction incorporatingthe improved sealing assemblies.

In accordance with the present invention there is provided an improvedsealing assembly for sealing the sides of control gates in a directionparallel to the direction of movement of the slide, that employs anelastomeric seal having a U-shaped cross-section. The seal is mounted inthe guide means along the sides of the opening and both arms of theU-shaped seal bear against one surface of the slide when the slide is ina closed position to seal it against water flowing past the side of theslide no matter on which side of the slide the water is located. Thearms of the U-shaped seal flex out slightly in opposite directions whentheir free edges contact the slide at two parallel locations along eachside. The seal is preferably constructed to enhance this movement. Theresiliency of the seal causes the free edges of both arms to beartightly against the slide thus blocking the flow of water past the sealfrom either direction. Thus the seal is double-acting in the sense thatit can be used in the same position to prevent flow of water past theslide no matter which side of the slide the water is on. The U-shapedcross-section of the seal allows the seal to be mounted centrally thuspermitting it to be positioned close to the edge of the opening andthereby requiring less mounting space.

The present invention also provides an improved sealing assembly forsealing control gates in a direction transverse to the direction of theslide travel. This sealing assembly employs a first sealing strip ofelastomeric material mounted on one of the slide or a frame on the walladjacent the top or bottom of the opening and having an angled sealingsurface. A second sealing strip of elastomeric material is mounted onthe other of the slide or frame and also has an angled sealing surface.The second sealing strip has a lateral projection adjacent its sealingsurface. The two sealing strips are mounted to have their sealingsurfaces face each other in an overlapping relationship. When the slideis moved relative to the frame to have the two sealing strips abut, theresilient, lateral projection gives slightly allowing the two angledsealing surfaces to make excellent sealing contact while wedgingtogether. With one sealing strip designed to give slightly, thetransverse sealing assemblies at both the top and bottom of the slideseal better since simultaneous sealing is not absolutely essential.

The invention is particularly directed toward a sealing assembly for acontrol gate of the type having: a frame mounted about an opening in awall, and a slide movable relative to the frame to open or close theopening, the frame having at least one straight frame plate mountedagainst the wall adjacent the opening; said sealing assembly comprisingan elastomeric seal strip having a U-shaped cross-section defined by acentral web and a pair of arms extending transversely from the web,mounting means located between the arms, fastening means for fasteningthe mounting means to the one frame plate with the web of the seal stripsandwiched between the frame plate and the moving means, the mountingmeans dimensioned to have the arms of the seal strip project just pastthe mounting means when it is fastened to the frame plate so that thearms will resiliently contact the slide as the slide moves adjacent andparallel to the mounting means.

The invention is also directed toward a control gate incorporating thissealing assembly.

The invention is further directed toward a sealing assembly for acontrol gate of the type having: a frame mounted about an opening in awall, and a slide movable relative to the frame to open or close theopening, the frame having at least one straight frame plate mountedagainst the wall and extending transversely to the direction of movementof the slide; said seal assembly having a first elastomeric seal stripadapted to be mounted on the frame plate, a second elastomeric sealstrip adapted to be mounted on the slide, one of the seal strips havinga bendable portion that projects in the path of relative movement of theother seal strip whereby when the two strips abut, the projectingportion gives slightly to give better sealing.

The invention is also directed toward a control gate incorporating thissealing assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a control gate;

FIG. 2 is a cross-section view of a portion of the control gateoperating means;

FIG. 3 is a cross-section view taken along line 3--3 of FIG. 1;

FIG. 4 is a cross-section view taken along line 4--4 of FIG. 1;

FIG. 5 is a cross-section view of the seal strip in the first sealingassembly;

FIG. 6 is a cross-section view of a modified seal strip in the firstsealing assembly;

FIG. 7 is a cross-section view of the top sealing assembly just beforethe slide closes the opening;

FIG. 8 is a cross-section view of the top sealing assembly with theslide closing the opening; and

FIG. 9 is a cross-section view of the bottom sealing assembly with theslide closing the opening.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, a control gate 1 is provided to control the flow ofwater, or other liquid, through an opening 3 in a wall 5. The controlgate 1 has a slide 7 mounted for up and down sliding movement adjacentone side 9 of the wall 5 to uncover or close the opening 3. The controlgate 1 also has a guiding and sealing frame assembly 11 mounted on theone side 9 of the wall 5 about the opening 3. The frame assembly 11 hasa pair of parallel, side guide means 13, each mounted on the side 9 ofthe wall 5 adjacent one of the sides 15 of the opening 3. Each guidemeans 13 extends vertically from the bottom 17 of the opening 3 to aposition well above the top 19 of the opening. The sides 21 of the slide7 are guided in the guide means 13 during up and down movement of theslide 7. The frame assembly 11 includes a bottom frame member 23 mountedon the side 9 of the wall 5 adjacent the bottom 17 of the opening 3. Thebottom frame member 23 extends under, and adjacent to, the bottom ends25 of the guide means 13 and acts as a stop for the slide 7. The bottomside 27 of the slide 7 abuts the bottom frame member 23 when the slide 7closes the opening 3. The frame assembly 11 also has a top frame member29 which extends between the guide means 13. The top frame member 29 ismounted on the side 9 of the wall 5 and is located adjacent the top side19 of the opening 3. The top side 31 of the slide 7 is located adjacentthe top frame member 29 of the frame assembly 11 when the slide 7 closesthe opening 3.

The control gate 1 includes operating means 37 for moving the slide 7 upor down. The operating means 37 as shown in FIG. 1, has a vertical rod39 fixedly mounted at its lower end 41 to a mounting block 43 fixed toback or outer side 45 of the slide 7 at about its center. The verticalrod 39 extends upwardly from the slide 7 through vertically spaced apartguide means 47 mounted on the side 9 of the wall 5. The rod 39 is freeto move up or down relative to the guide means 47. The upper portion 49of the rod 39 is threaded and freely passes up through a support tube 51mounted on the top 53 of the wall 5 as shown in FIG. 2. A ring 55 isrotatably mounted at the top 57 of the tube 51. The outer surface of thering 55 has a first bevel gear 59 formed thereon. The inner bore 61 ofthe ring is threaded. The rod 39 is threaded through the bore 61. Means63 are provided for rotating the ring 55 within its mounting in the top57 of the tube 51. These means include a crank rod 65 rotatably mountedwithin the top 57 of the tube 51 and extending transversely therefrom. Asecond bevel gear 67 is mounted at one end of the crank rod 65 to meshwith the first bevel gear 59. A crank handle 69 is mountd on the otherend of the crank rod 65 outside of the tube 51. Rotation of the crankhandle 69 will rotate the ring 61 within the tube 51 causing the rod 39to rise or lower, depending on which way the ring 61 is rotated, andthus lifting or lowering the slide 7 to open or close the opening 3.While one form of operating means 37 for moving the slide 7 has beendescribed, other forms of operating means can be employed.

Each guide means 13 for guiding the slide 7 during its up or downmovement has an inner plate 73 and a parallel outer plate 75 as shown inFIG. 3. The outer plate 75 is spaced from the inner plate 73 by a pairof spacer bars 77, 79. The first spacer bar 77 is welded to inner plate73 adjacent one side 81 of the inner plate 73. The second spacer bar 79is spaced a short distance from the first bar 77 and also welded to theinner plate 73. The spacer bars 77, 79 are parallel to each other andextend transversely from the inner plate 73. Mounting means 83 mount theinner plate 73 against the side 9 of the wall 5 with its other side 85generally adjacent the side 15 of the opening 3. A gasket 87 isinterposed between the inner plate 73 and the side 9 of the wall 5. Themounting means 83 also connects the outer plate 75 against the outerends 89, 91 of the spacer bars 77, 79 to position it relative to theinner plate 73. The mounting means 83 comprises a row of anchor bolts 93set in the wall 5 which extend transversely from the side 9 of the wall5. Each bolt 93 passes through an opening 95 in the inner plate 73, andopening 97 in the outer plate 75 and through the gasket 87. Each bolt 93also passes between the spacer bars 77, 79. The gasket 87 and plates 73,75 are mounted on the anchor bolts 93 and a washer 99 and nut 101 oneach bolt 93 connects the plates 73, 75 to each other and to the wall 5.

When the plates 73, 75 are mounted on the wall 5 and to each other, theydefine a slot 103 facing toward the opening 3 in the wall 5. A side edge21 of the slide 7 is guided in the slot 103 of the guide means 13 duringup and down movement of the slide 7 as shown in FIG. 4. A sealingassembly 111 is provided in the slot 103 of each guide means 13 tosecurely guide and tightly seal the slide 7 in the guide means 13. Thesealing assembly 111 comprises a seal strip 113 made from a suitableelastomeric material such as a hard rubber. The seal strip 113, as shownin FIG. 5, has a U-shaped cross-section defined by a central web 115 anda pair of arms 117 extending transversely from the sides of the web 115.The two outer corners of the seal strip 113 are preferably bevelled asshown at 119, 121. The bevelling allows the arms 117 to pivot slightlyaway from each other, about their connections to the web 115 whensealing the slide 7, as will be described. In an alternative embodiment,as shown in FIG. 6, the corners of the seal strip 113' can be undercutas shown at 123, 125. The undercutting serves the same purpose as thebevelling, allowing the arms 117' to pivot slightly away from eachother, about their connections to the web 115'.

Mounting means 131 are provided in the sealing assembly 111 for mountingthe seal strip 113 within the slot to the guide means 13. The seal strip113 is mounted to the inner plate 73 closely adjacent the other side 85of the inner plate. The mounting means 131 includes a flat mountingplate 135 that is sized to fit into the seal strip 113 against its web115 between the arms 117. The mounting plate 135 is preferably made ofstainless steel. The mounting means 131 also preferably include a firstguide strip 137. The guide strip 137 overlies the mounting plate 135 andis also located between the arms 117 of the seal strip 113. The firstguide strip 137 is made from material which has good wear properties anda low coefficient of friction such as an ultra high molecular weightpolyethylane. The first guide strip 137, and the mounting plate 135, aremade to have a thickness, together, such that when both are mounted tothe inner plate 73, with the web 115 of the seal strip 113 sandwichedbetween them, the ends 139 of the arms 117 of the seal strip 113 projectjust slightly past the outer surface 141 of the first guide strip 137.The mounting plate 131 and the first guide strip 141 are fastened to theinner plate 73 with suitable fastening means such as screws 143 with theweb 115 of the seal strip 113 sandwiched between the mounting plate 131and the inner plate 73. The screws 143 pass through the web 115.

The sealing assembly 111 also includes a second guide strip 147. Thesecond guide strip 147 is made from the same material as the first guidestrip 137 and is mounted opposite the first guide strip on the innersurface 149 of the outer plate 75 by adhesive or other suitable means(not shown). The dimensions of the slot 103 and the members of thesealing assembly 111 are selected to have the width of the gap 151between the facing surfaces 141, 153 of the guide strips 137, 147respectively just slightly wider than the thickness of the edge of theslide 7 that enters the slot 103 and gap 151 to lie between the guidestrips 137, 147 to be guided.

In use, the scaling assembly 111 seals the slide 7 to the guide means 13on the frame assembly 11 to prevent water flowing past the sides of theslide while it covers the opening 3. The slide 7 moves in the slot 103in the guide means 13 and in the gap 151 in the sealing assembly 111with its inner and outer surfaces 155, 45 lying closely adjacent to thefirst and second guide strips 137, 147 respectively. While in betweenthe guide strips 137, 147, the slide 7 contacts the ends 139 of the arms117 of the seal strip 113, bending them slightly outwardly. The arms 117can bend outwardly slightly because of the bevel or undercutting on theouter corners where the arms 117 join the web 115. The resiliency of theseal strip 113 causes the bent arms 117 to tightly bear against theinner surface 155 of the slide 7, while pushing the slide against theinner surface 153 of second guide strip 147. The arms 117 of the sealstrip 113 prevent any water from flowing around the sides 21 of theslide 7.

A second seal assembly 161 is provided to seal the top side 31 of theslide 7 to the top frame member 29 of the frame assembly 11. As shown inFIG. 7, the top frame member 29 comprises a flat plate 163 extendingacross the side 9 of the wall 5 between the guide means 13. The loweredge 165 of the top plate 163 is generally aligned with the top side 19of the opening 3. Machine screws 167 fasten the top plate 163 to thewall 5, the screws passing through countersunk holes in the top plateand connecting to sockets or plugs 169 set in the wall 5. A sealinggasket 171 is interposed between the top plate 163 and the wall 5 withthe screws 167 passing through the gasket.

The second seal assembly 161 has a first seal member 175 made in theform of a strip. The strip, when viewed in cross-section, has a flatmounting side 177 extending between two narrow edges 179, 181. The otherside of the strip has an angled surface 183 that slopes toward onenarrow edge 179. The other side is also stepped down from the angledsurface 183 as shown at 185 to a flat surface 187 that extends from thestep 185 to the other edge 181 and is generally parallel to the flatside 177. The first seal member 175 is made of a suitable resilientmaterial such as fairly hard rubber having a durometer harness of 60 to65.

A flat mounting plate 191, thinner than the depth of stop 185, is sizedto fit over the flat surface 187. The mounting plate 191, made of metal,is used to fasten the first seal member 175 to the top plate 163 withits flat side 177 against the plate 163 and its angled surface 183 atthe top. The mounting plate 191 is fastened to the top plate 163 withsuitable fasteners 193 with the lower part of the seal member 175sandwiched between them. The bottom edge 181 of the seal member 175 isgenerally aligned with the bottom edge 165 of the top plate 163. It willbe noted that a portion 195 of the seal member 175 projects past themounting plate 191.

The second seal assembly 161 also has a second seal member 201 in theform of a strip. This second seal member, when viewed in cross-section,has a flat mounting side 203, a first bevelled edge 205, a second squareedge 207, and an outer side 209. The outer side 209 is stepped down asshown at 211 toward the square edge 207. This second seal member 201 isalso made of suitable resilient material such as fairly hard rubberhaving a durometer hardness of 70 to 75. A flat mounting plate 213,sized to fit into the stepped down portion of the seal member 201, isused to fasten it to the inner side 155 of the slide 7, adjacent its topside 31, with the bevelled edge 205 facing down. The mounting plate 213is fastened to the slide 7 with the second seal member 201 sandwichedbetween them with suitable fasteners 215.

In use, as the slide 7 reaches its bottom position to close the opening,the bevelled edge 205 of the second seal member 201 on the slide 7contacts the angled surface 183 of the first seal member 175 on theframe. The contact is made at the projecting portion 195. Thus theslightly harder second seal member 201 can push against the projectingportion of the first seal member 175 to ensure a good seal between theslide and frame. The projecting portion 195 of the first seal member 175will both give slightly, and move down slightly over the mounting plate191 to make good sealing contact with the second seal member 201, asshown in FIG. 8.

In an alternative arrangement, the first seal member 175 could bemounted on the slide 7 in a reversed position, and the second sealmember 201 could be mounted on the frame, also in a reversed position,so that seal member 175 is moved relative to seal member 201.

A third seal assembly 221 is provided at the bottom of the control gate.The third seal assembly 221 is mounted on the bottom frame member 23. Asshown in FIG. 9, this bottom frame member 23 comprises an angle memberhaving first and second legs 223, 225. The bottom frame member 23 ismounted against the side 9 of the wall 5 with the first leg 223 againstthe wall and the second leg 225 extending transversely therefrom. A setof anchor bolts 227, set in the wall 5, is used to mount the angle ontothe wall. Nuts 229 securely fasten the angle against the wall 5 with agasket 231 interposed between them. A sealing member 233, in strip form,is fastened to the top surface of the second leg 225. The sealing member233 has a generally rectangular shape except for a step 235 on its top,outer side. A mounting plate 237 fits in the step 235 and is fastened tothe leg 225 with suitable fastening means 239, sandwiching the sealingmember 233 between it and the leg 225. The sealing member 233 is madefrom suitable resilient material, such as a hard rubber.

In use, when the control gate 1 is closed, the slide 7 contacts the topsurface 241 of the sealing member 233 swich its bottom edge 27. Thiscontact occurs simultaneously with contact being made in the secondsealing assembly between the slide 7 and the frame 29 so as to seal theslide 7 at the top and at the bottom. With the slide 7 also sealed atits sides, the slide 7 closes the opening 3 to water flow.

The bottom ends of the side seal strips 113 in the side guide means 13abut the top surface 241 of the bottom sealing member 233 and arefastened to the bottom sealing member 233 by vulcanizing or othersuitable means. Similarly the ends of the first seal member 175 in thesecond seal assembly at the top of the frame 11 abut the side sealstrips 113 in the first seal assembly 111 and are fastened thereto byvulcanizing or other suitable means. Thus a watertight seal assembly isformed about the frame 11.

A seal assembly similar to the second seal assembly 161, used at the topof the frame and the slide, could also be used at the bottom, replacingthe third seal assembly 221 if desired. Also the first seal assembly111, without the second seal strip 147, could be used at the top of theframe, replacing the second seal assembly 161. Both seal strips 175, 201of the second seal assembly 161 would be removed and the first sealassembly 111 could be mounted on frame plate 163 to have the arms 117 ofits seal strip 113 abut the inner surface 155 of the slide 7 near itstop edge 31.

I claim:
 1. A sealing assembly for a control gate of the type having; aframe mounted about an opening in a wall; and a slide movable relativeto the frame to open or close the opening, the frame having a firststraight frame plate mounted against the wall adjacent the opening and asecond straight frame plate, parallel to, but spaced from the firstframe plate, the frame plates defining a guide slot between them inwhich the side of the slide moves; the sealing assembly located in theguide slot and having an elastomeric seal strip with a U-shapedcross-section defined by a central web and a pair of arms extendingtransversely from the sides of the web, mounting means located betweenthe arms, means fastening the mounting means to the first frame platewith the web of the seal strip sandwiched tightly between the firstframe plate and the mounting means, the mounting means spaced from thesecond frame plate a distance slightly greater than the thickness of theside of the slide, the free ends of the arms of the seal strip spacedfrom the second frame plate a distance slightly less than the thicknessof the side of the slide.
 2. A sealing assembly as claimed in claim 1wherein the mounting means includes an inner mounting plate and an outerguide strip, the second frame plate having a second guide strip locatedopposite the first guide strip, both guide strips made from a materialhaving a low coefficient of friction.
 3. A sealing assembly as claimedin claim 1 wherein each arm extends transversely from the web at acorner of the seal strip, said corner being bevelled thereby allowingthe arm to bend outwardly away from the other arm slightly more easilywhen the arms are contacted by the slide.
 4. A sealing assembly asclaimed in claim 1 wherein each arm extends transversely from the web ata corner of the seal strip, said corner being undercut thereby allowingthe arm to bend outwardly away from the other arm slightly more easilywhen the arms are contacted by the slide.
 5. A control gate having aframe with top, bottom and side frame members mounted about an openingin a wall, a slide having a top, bottom and sides movable relative tothe frame to open or close the opening, the side frame members eachhaving an inner side plate and an outer side plate forming a guide slotto receive the sides of the slide, a sealing assembly within the slot,the sealing assembly having an elastomeric seal strip with a U-shapedcross-section defined by a central web and a pair of arms extendingtransversely from the sides of the web, mounting means located betweenthe arms, fastening means for fastening the mounting means to one of theside plates within the slot with the web of the seal strip sandwichedtightly between the mounting means and the one side plate, the mountingmeans dimensioned to have the arms of the seal strip project just pastthe mounting means toward the other side plate when it is fastened tothe one side plate so that the arms will resiliently contact the slideas it moves in the slot between the mounting means and the other sideplate.
 6. A control gate as claimed in claim 5 including a secondsealing assembly extending transverse to the direction of movement ofthe slide, said second sealing assembly having a first elastomeric sealstrip mounted on one of the frame or slide, a second elastomeric sealstrip mounted on the other of the frame or slide, one of the first andsecond seal strips having an abutting portion that projects into therelative path of movement of the other seal strip, said one seal stripfixed to have the projecting abutting portion bend in the direction ofrelative movement when abutted by the other seal strip.
 7. A controlgate as claimed in claim 19 wherein the mounting means comprises aninner mounting plate and an outer guide strip.
 8. A control gate asclaimed in claim 7 wherein the sealing assembly includes a second guidestrip mounted within the slot on the other side plate opposite thefirst, outer guide strip, the two guide strips defining a gap justslightly wider than the thickness of the slide and the arms of the sealstrip extending into the gap.
 9. A control gate as claimed in claim 19wherein each arm extends transversely from the web at a corner of theseal strip, said corner being bevelled thereby allowing the arm to bendoutwardly away from the other arm slightly more easily when the arms arecontacted by the slide.
 10. A control gate as claimed in claim 5 whereineach arm extends transversely from the web at a corner of the sealstrip, said corner being undercut thereby allowing the arm to bendoutwardly away from the other arm slightly more easily when the arms arecontacted by the slide.
 11. A control gate as claimed in claim 6 whereinsaid one seal strip is slightly softer than the other seal strip toprovide fore better sealing.
 12. A control gate having a frame withgenerally vertical and horizontal side members mounted about an openingin a wall, a slide having vertical and horizontal sides movable relativeto the frame to open or close the opening, a sealing assembly at one ofthe horizontal sides of the frame and slide, the sealing assembly havinga first elastomeric seal strip mounted on one of the frame or slide, asecond elastomeric seal strip mounted on the other of the frame orslide, one of the first and second seal strips having an abuttingportion that projects into the relative path of movement of the otherseal strip, said one seal strip fixed to have the projecting abuttingportion bend in the direction of relative movement when abutted by theother seal strip.
 13. A control gate as claimed in claim 12 wherein saidone seal strip is made of slightly softer material than the other sealstrip.
 14. A sealing assembly for a control gate of the type having: aframe mounted about an opening in a wall, and a slide movable relativeto the frame to open or close the opening, the frame having at least onestraight frame plate mounted against the wall and extending transverselyto the direction of movement of the slide; said sealing assembly havinga first elastomeric seal strip adapted to be mounted on the frame plate,a second elastomeric seal strip adapted to be mounted on the slide, oneof the seal strips having an abutting portion that projects into therelative path of movement of the other seal strip, said one seal stripfixed to have the projecting abutting portion bend in the direction ofrelative movement when abutted by the other seal strip.